Processing and application of a purification system for gold mining, extraction of minerals and growth of algae biomass

ABSTRACT

The present disclosure describes a process for using saline water, and saline reject water produced in water purification, to use for gold mining production, and growing and harvesting algae. The disclosure also describes a method for growing and harvesting algae utilizing saline water as growth medium for recycling waste water to extract the remaining metals out of waste water. The harvested algae may be used in various applications including but not limited to water purification for gold mining production and to extract metals out of remaining waste water.

BACKGROUND OF THE INVENTION

1. Technical Field

The present disclosure relates to a method for the concurrent productionof algae and the separation of gold from a gold ore using an algal matand a system for the production of algae and the separation of gold froma gold ore using an algal mat.

2. Description of the Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

Algae thrive in turbid, brackish water environments with little morethan basic nutrients and sunshine. They grow far more rapidly thanconventional crops, and generate a much higher fraction of their biomassas oil (up to 60%, versus 2%-3% for soybeans).

As recently, algae have become significant organisms for biologicalpurification of wastewater since they are able to accumulate plantnutrients, heavy metals, pesticides, organic and inorganic toxicsubstances and radioactive matters in their cells/bodies (Kalesh N S,Nair S M The Accumulation Levels of Heavy Metals (Ni, Cr, Sr, & Ag) inMarine Algae from Southwest Coast of India. Toxicological &Environmental Chemistry 2005; 87(2): 135-146; Jothinayagi N, AnbazhaganC. Heavy Metal Monitoring of Rameswaram Coast by Some Sargassum species.American-Eurasian Journal of Scientific Research 2009; 4 (2): 73-80; AlpM T, Sen B, Ozbay O. Heavy Metal Levels in Cladophora glomerata whichSeasonally Occur in the Lake Hazar. Ekoloji, 20 (78): 13-17. doi:10.5053/ekoloji.2011.783; Alp M T, Ozbay O, Sungur M. A. Determinationof Heavy Metal Levels in Sediment and Macroalgae (Ulva sp. andEnteromorpha sp.) on the Mersin Coast 2011. Ekoloji 21, 82, 47-55(2012)—each incorporated herein by reference in its entirety). Thesespecific features have made algal wastewater treatment systems asignificant low-cost alternative to complex expensive treatment systemsparticularly for purification of municipal wastewaters.

In addition, algae harvested from treatment ponds are widely used asnitrogen and phosphorus supplements for agricultural purpose and can besubjected to fermentation in order to obtain energy from methane. Algaeare also able to accumulate highly toxic substances such as selenium,zinc and arsenic in their cells and/or bodies thus eliminating suchsubstances from aquatic environments. Radiation is also an importanttype of pollution as some water contains naturally radioactivematerials, and others become radioactive through contamination. Manyalgae can take up and accumulate many radioactive minerals in theircells even from greater concentrations in the water (Palmer, C. M. Acomposite rating of algae tolerating organic pollution. J. Phycology.1969; 5: 78-82—incorporated herein by reference in its entirety).MacKenthun emphasized that Spirogyra can accumulate radio-phosphorus bya factor 850.000 times that of water (MacKenthun, K. M. Radioactivewastes. Chapt 8. İn The Practice of Water Pollution Biology. U.S. Dept.Interior, Fed. Water Pol. Contr. Admin., Div. of Tech. Support. U.S.Printing Office 1969—incorporated herein by reference in its entirety).

It is well known that algae have an important role in self-purificationof organic pollution in natural waters (

en, B. ve Nacar, V. Su Kirlili{hacek over (g)}i ve Algler. F

rat Havzas

I.

evre Sempozyumu Bildiriler Kitab

. 1988; 405-21—incorporated herein by reference in its entirety).Moreover, many studies revealed that algae remove nutrients especiallynitrogen and phosphorus, heavy metals, pesticides, organic and inorganictoxins, pathogens from surrounding water by accumulating and/or usingthem in their cells (Reddy, K. R. Fate of Nitrogen and Phosphorus in aWastewater Retention Reservoir Containing Aquatic Macrophytes. Journalof Environmental Quality, 1983; 12(1):137-41; Lloyd, B. J. andFrederick, G. L. Parasite removal by waste stabilisation pond systemsand the relationship between concentrations in sewage and prevalence inthe community, Water Science and Technology 2000; 42(10):375-86—eachincorporated herein by reference in its entirety). Also, studies showedthat algae may be used successfully for wastewater treatment as a resultof their bioaccumulation abilities (Oswald, W. J. The role of microalgaein liquid waste treatment and reclamation. In: C. A. Lembi and J. R.Waalnd (eds). Algae and Human Affairs, Cambridge University Press 1988a;403-31—incorporated herein by reference in its entirety).

Wastewater treatment systems which are applied to improve or upgrade thequality of a wastewater involves physical, chemical and biologicalprocesses in primary, secondary or tertiary stages. Primary treatmentremoves materials that will either float or readily settle out bygravity. It includes the physical processes of screening, contamination,grit removal, and sedimentation. While the secondary treatment isusually accomplished by biological processes and removes the solubleorganic matter and suspended solids left from primary treatment.Tertiary or advanced treatment is process for purification in whichnitrates and phosphates, as well as fine particles are removed (Droste,R. L. Theory and Practice of water and wastewater treatment, John Wileyand Sons, New York 1997—incorporated herein by reference in itsentirety). However initial cost as well as operating cost of wastewatertreatment plant including primary, secondary or advanced stages ishighly expensive (Oswald, W. J. Ponds in twenty first century. WaterScience and Technology 1995; 31(12):1-8—incorporated herein by referencein its entirety).

Some algae produce lipids that can be converted to biodiesel or greendiesel. Some strains produce ethanol. Algae biomass is also used asfood, animal feed and fertiliser, but it isn't reasonable to expect 100%substitution—there are too many complications. In 20 years fuelsubstitution is expected to be in the 5%-8% range.

Creating biofuels from microbes has many advantages. Algae can grow inlow lying areas unsuitable for conventional crops. Algae can yield 8,000liters of fuel per acre per year, compared with 2,600 liters for palmoil and 200 liters for soy. Algae can use brackish water or wastewateras a growing medium, eliminating the freshwater needs of ethanolproduction. Algae production does not compete with food crops such ascorn or soy for acreage, nutrients or fresh water. Furthermore, biofuelsare similar enough to gasoline and diesel that they do not requirespecial treatment during transportation and mixing at the refinery.

Recent studies conclude that this algae dewatering process costs over$3,000 in energy alone to produce one ton of dry weight biomassequivalent, making algae an uneconomic source of fuel when compared tofossil fuels. Nevertheless, a comprehensive industry survey undertakenby the Algal Biomass Organization last year found that more than 35% ofindustry participants believe it is either very likely or extremelylikely that algae-based fuels will be cost-competitive with fossil fuelsby 2020.

BRIEF SUMMARY OF THE INVENTION

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The described embodiments, together with further advantages,will be best understood by reference to the following detaileddescription taken in conjunction with the accompanying drawings.

One embodiment of the disclosure describes a process for gold mining andalgae production.

In another embodiment the process comprises treating a salt water streamhaving a first salt concentration, wherein the treating is carried outwith at least one of electrodialysis reversal, reverse osmosis ormechanical vapor compression in a first water purification system toform: (i) a first purified water stream having a second saltconcentration lower than the first salt concentration, and (ii) a firstsaline water stream having a third salt concentration higher than thefirst salt concentration.

In another embodiment the process comprises treating a gold ore with thefirst purified water stream to separate gold from the gold ore and toform a first waste water.

In another embodiment the process comprises treating the waste watercomprising metal ions in a waste water processing unit comprising analgae mat to form (i) a third purified water stream and (ii) the algaemat bound to the metal ions, and further treating the gold ore with thethird purified water stream.

In another embodiment the process comprises feeding the first salinewater stream to a bioreactor containing algae to form a first biomass inthe saline water of the first saline water stream and to form a firstsaline biomass stream.

In another embodiment the process comprises feeding the first salinebiomass stream to an algae growth and harvesting chamber to grow thealgae and to form a concentrated biomass.

In another embodiment the process comprises feeding the concentratedbiomass to the waste water processing unit and forming a filter in theform of an algae mat from the biomass in the waste water processingunit.

In another embodiment the process comprises removing the algae mat fromthe waste water processing unit and isolating gold and oil from thealgae mat.

In another embodiment the disclosure describes a system for gold miningand algae production.

In another embodiment the system comprises a first water purificationsystem that treats a salt water stream having a first salt concentrationand forms a first purified water stream having a second saltconcentration lower than the first concentration and a first salinewater stream having a third salt concentration higher than the firstconcentration.

In another embodiment the system comprises a gold mining productionsystem that treats a gold ore with the first purified water stream toseparate gold from the gold ore and to form a first waste water.

In another embodiment the system comprises a waste water processing unitcomprising an algal mat that treats the waste water comprising metalions to form a second purified water stream and the algae mat bound tothe metal ions wherein the waste water processing unit further treatsthe gold ore with the second purified water stream and/or an algal matformed by producing algae in a waste water stream.

In another embodiment the system comprises a bioreactor containing algaethat forms a first biomass in the saline water of the first saline waterstream and forms a first saline biomass stream wherein the first salinewater stream is fed to the bioreactor containing algae.

In another embodiment the system comprises an algae growth andharvesting chamber that grows the algae to form a concentrated biomassby feeding the first saline biomass stream to the algae growth andharvesting chamber wherein the concentrated biomass is fed to the wastewater processing unit and forms a filter in the form of an algae matfrom the biomass in the waste water processing unit.

In another embodiment the system isolates gold and oil from the algaemat.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 illustrates a flow diagram for using salt water for gold miningproduction.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views.

The economic and environmental incentive to reduce the energy costsassociated with algae processing is driving increased levels of industryresearch, particularly on ways to reduce the cost of algae dewatering.Pall Corporation, for example, has developed the algae separation andconcentration filter (ASCF) that uses a hollow-fiber filter technologyfor chemical cleaning to remove organic and inorganic debris.

One of the common associations with gold in detrital deposits is theassociation of gold with uranium and carbon. This holds true in theWitwatersrand and all the other gold deposits of a detrital nature. Formany years the origin of the carbon was hotly debated with the mostrecent evidence holding that it is from primitive life forms that livedin the distant past in the Archean.

Algae exposed at the intertidal zone similar to the ancient algae thattrapped gold. Even today this kind of mat could be a good place tosearch for gold. It has been posited that these algae formedstromatolite-type structures that acted as a trap for gold and uraniumminerals.

Many gold bearing deposits are located at the bottom of a ancient streamchannel. The gold was deposited by dropping from suspension to formstringers of gold. These stringers of gold are common in detrital golddeposits. Sometimes there is a layer of carbon that is as thin as apencil line that is so rich in gold and other minerals that they aremineable. In many detrital deposits the slim lines occur at a regularfrequency to the extent that the entire deposit is mined so that it canundergo further ore dressing to free the gold so it can undergo evenfurther treatment usually by being leached with a solution of cyanide.

The inland brackish water that constitute the feed for waterpurification plants has a higher quality (i.e. lower salinity) comparedto seawater and is more suitable for water purification. Depending onlevel of salinity and cost, various methods are utilized for purifyingthe brackish water, such as reverse osmosis (RO), electro-dialysisreversal (EDR), or similar membrane techniques. Water purificationprocess of brackish water produces purified water and saline rejectwater as main product and by-product, respectively. The produced salinereject water usually contains a higher concentration of various salts inwater compared to the brackish water. A number of subsequentpurifications may be performed to extract the remaining purified waterfrom the saline reject water. However, the salinity of the saline rejectwater increases after each subsequent purification, leading to increasedcost, and complexity of the water purification procedure. Therefore,after a number of purification steps, the saline reject water becomeshighly saline.

The highly saline reject water is considered as waste in thepurification process and therefore is disposed. However, disposing suchhighly saline reject water is complicated and costly. Because of thecosts and problems associated with the disposal of the highly salinereject water, there exists a need for developing methods for minimizingsuch undesirable liquid by-products, or recycling and/or transformingthe waste into a valuable product. Moreover, extracting gold by usingfresh water is expensive.

In one embodiment the disclosure describes a method for using highlysaline water and/or a water stream obtained by treating saline waterwith an algae growth system, as an alternative to disposal, to produce avariety of valuable products such as gold mining production, and growingalgae to extract metals. In addition the method also recycles the wastewater for the production of gold mining.

According to one embodiment, FIG. 1 depicts a process flow diagram forusing brackish/saline water for gold mining production. First, a streamof water 14 having a salinity content of 0.05% salinity or greater issupplied to a first water purification system 1. The stream of water 14may be brackish water, saline water, or any combination thereof. Astream having a combination of brackish water and saline water may havea brackish and saline percent composition including but not limited to50% brackish water and 50% saline water, 20% brackish water and 80%saline water, 80% brackish water and 20% saline water, 30% brackishwater and 70% saline water, 70% brackish water and 30% saline water,100% brackish water, or 100% saline water. The brackish water has asalinity in the range of 0.5-30 grams of salt per liter, 5-20 grams ofsalt per liter, or 10-15 grams of salt per liter. The saline water has asalinity in the range of 30-50 grams or salt per liter, 32-48 grams ofsalt per liter, or 35-45 grams of salt per liter. The brackish waterand/or the saline water may be supplied from water resources includingbut not limited to river water, lake water, ocean water and/or anotherwater purification system, e.g., reverse osmosis or distillativedesalinization. The brackish water and/or the saline water may alsocomprise magnesium (Mg) and sulphate (SO₄) ions in dissolved form.

The first water purification system 1 removes suspended solids and/orgases from the brackish water 14 and produces a first stream of purifiedwater 16 and a first stream of saline reject water 15. The waterpurification system reduces the concentration of salt in the waterstream so that the purified water 16 has a lower concentration of saltthan the stream of water 14 and so that the stream of saline rejectwater 15 has a higher concentration of salt than the stream of water 14.The purified water 16 produced by the first water purification system 1may have various purity levels to provide water for human consumption,animal consumption or agricultural purposes. The purified water 16 isstored in a purified water reservoir 3.

The stream of saline reject water 15 is supplied to a second waterpurification system 2 that further processes the saline reject water toproduce a stream of highly saline reject water 18 and a second stream ofpurified water 17. The stream of highly reject saline water 18 has ahigher concentration of salt than the stream of saline reject water 15.The second stream of purified water 17 has a lower salt concentrationthan the stream of saline reject water 15. The first stream of purifiedwater 16 and the second stream of purified water 17 are both stored in apurified water reservoir 3. The purified water by the first stream ofpurified water 16 and the second stream of purified water 17 may also begathered in a plurality of water reservoirs.

In one embodiment the water purification system 1 and the waterpurification system 2 are of the same configuration. The waterpurification system 1 and the water purification system 2 comprise anintake chamber; an osmotic chamber coupled to the intake chamber; atleast one ammonia stripping column coupled to the osmotic chamber; atleast one ion exchange coupled to the at least one ammonia strippingcolumn; a breakpoint chlorination chamber coupled to the at least oneion exchange column; and an output from the breakpoint chlorinationchamber.

In another embodiment the stream of brackish/saline water 14 enters anintake chamber of the water purification system 1 or the stream ofsaline reject water 15 enters the water purification system 2. Theintake chamber directs the seawater from the intake chamber into anosmotic chamber, allowing osmosis of water molecules through a membranelocated between the seawater and a concentrated ammonia solution in theosmotic chamber. In the osmotic chamber the concentrated ammoniasolution is converted to a diluted solution through osmosis. The pH ofthe diluted solution is adjusted to a pH of 11 or higher. Ammonia isremoved from the diluted solution using multistage air-stripping columnswhich adjusts the pH of the diluted solution to approximately neutralafter the air-stripping. Then the ammonia is removed from the dilutedsolution using at least one ion-exchange column after the air-strippingand the ammonia is removed from the diluted solution using breakpointchlorination after ion exchange. Breakpoint chlorination includes addinga solution of chlorine to the water so that the ammonia may be oxidizedand removed and only free chlorine remains.

In another embodiment osmosis occurs between seawater and a secondsolution, resulting in a diluted solution. The ammonia is stripped fromthe diluted solution at an elevated pH level, and ammonia is removedfrom the diluted solution using ion exchange. Breakpoint chlorination isthen performed on the diluted solution to effectively remove anyremaining ammonia.

The water purification systems 1 and 2 convert water having a salinitycontent of 0.05% or higher to purified water by undergoing osmosis witha concentrated ammonia solution, removing ammonia from the solution(ammonia concentration of 500 mg/L or less) using air-stripping columnsat an elevated pH, removing ammonia from the solution using ion-exchangemethods, and a breakpoint chlorination step to remove any remainingammonia in the solution.

In another embodiment the water purification system 1 and the waterpurification system 2 may include a plurality of chambers for differentprocessing stages. The first chamber may be a seawater intake chamber,which may be equipped with a microstrainer, typically for removal ofobjects measuring at least 5 microns. In another embodiment the algaemay be used as a microstrainer. The intake chamber may be connected toan osmotic chamber. The osmotic chamber may have an osmotic membranewith a seawater tank on one side and an ammonia tank, containing aconcentrated ammonia solution, on the other side. The seawater may enterthe seawater tank from the intake chamber, and using the osmoticmembrane, water molecules may migrate into the ammonia tank to asolution that may typically contain approximately molar ammonia as asolute. The concentration of ammonia in the ammonia tank may be greatlydiluted, e.g. 5 times, through the osmotic process. The pH of thediluted solution may then be adjusted to 11 or higher, typically usingsodium hydroxide.

The solution may then be introduced to multistage air-stripping columnsto remove ammonia, typically to a concentration of 500 mg/L or less. Thecolumn packing material may be specially designed to achieve ammoniaremoval efficiency of 85% or better when using air for the strippingoperation. The gas stream coming out of the ammonia stripping columnsmay be a mixture of ammonia, oxygen, nitrogen, and water vapor. This gasstream may then be passed through condensation tube, which may typicallybe a series of longitudinal conduits designed to condense the ammoniaand the moisture content in the gas stream, allowing oxygen, nitrogen,and a low concentration of ammonia to escape. Subsequently, the escaped(post-condensation) gas stream may be directed to a heating chamber, andthe heated gas may then be recirculated back to the ammonia strippingcolumns. The condensate, containing water and ammonia, may then berecirculated back to the ammonia solution in the osmotic chamber.

The pH of the water after ammonia stripping may then be adjusted toalmost neutral (typically 6.5 to 7.5), using an acid including but notlimited to sulfuric acid. The water may then be passed through aplurality of ion exchange columns for ammonia removal which decreasesthe ammonia concentration in the water to less than 5 mg/L. The ionexchange resin is regenerated using an acid including but not limited toconcentrated sulfuric acid. This solution can be recirculated until thesolution is almost saturated with ammonium sulfate, and it may then bedischarged through a recirculating fluid output. Concentrated sodiumhydroxide solution may be used to adjust the pH of the solution to above11, and ammonia gas may eventually be removed by air stripping columns.The gas from the air stripping columns may be directed to thecondensation tube. The spent solution may contain high concentrations ofsodium ion, sulfate, and some residual ammonia, and the solution can bediluted with seawater before discharging back to the ocean.

The water may then undergo breakpoint chlorination, typically in achamber, in which the remaining ammonia in the water may be oxidized tonitrogen gas and chloramines using chlorine gas or hypochlorites. Theresulting water product may typically contain total dissolved solids of150 mg/L or less with a free chlorine level in the range of 0.2 mg/L to1 mg/L.

The ammonia concentration of the solution exiting the osmotic chambermay be in the range of 30,000 mg/L even after 5-time dilution throughthe osmotic process. The physical process of condensation may be used toseparate most of the air from the ammonia. The ammonia condensate may becompletely recirculated to the ammonia solution in the osmotic chamber,and the escaped air stream may be recirculated to the air strippingcolumns. A heat-exchange system may be used to extract heat from thecondensation process. The extracted heat may be used to heat therecirculated air stream.

The mixture of air and ammonia is discharged into the atmosphere ortreated with the biological processes of nitrification-denitrification.

In one embodiment the water purification system 1 and the waterpurification system 2 may provide a completely closed system withoutreleasing any ammonia to the atmosphere.

In another embodiment the water purification system 1 and the waterpurification system 2 treat the stream of saline water by a method ofelectrodialysis. NaCl separated during electrodialysis may be subjectedto electrolysis to form NaOH. The NaOH may be reacted with ammonia andCO₂ to form soda ash. MgOH₂ may also be precipitated and reacted withthe additive CO₂ to precipitate MgCO₃. MgCO₃ is then discarded throughan extract remaining metals unit 12.

The purified water reservoir 3 supplies the purified water to a goldmining production system 4. The gold mining production system 4comprises a gold ore. The gold ore comprises gold and other materialsincluding but not limited to silver, mercury, copper, sulfide,calaverite, sylvanite, nagyagite, petzite, and krennerite. The goldmining production system separates a gold compound 22 from the gold ore.Preferably the gold compound has a purity of gold of 50% or greater.More preferably the gold compound 22 is at least 90% pure gold.

The stream of highly saline reject water 18 has a salinity in the rangeof 50-500 grams of salt per liter, 100-400 grams of salt per liter, or150-350 grams of salt per liter.

The first water purification system 1 and the second water purificationsystem 2 may have systems including but not limited to reverse osmosis,electro-dialysis reversal, and mechanical vapor compressiondistillation.

In another embodiment the highly saline reject water 18 may be treatedin a treatment unit 5. The treatments in the optional treatment unit 5include but are not limited to treatment with a UV lamp, heating, oraddition of materials to change chemical or physical properties. Anadditive chamber 6 includes additives to be added to the treatment unit5. In one embodiment the additive chamber 6 comprises one container ofadditives. In another embodiment the additive chamber 6 has a pluralityof separate containers for storing materials to be added to thetreatment unit 5. The additive chamber 6 may include one separatecontainer or a plurality of separate containers for storing thematerials to be added to the optional treatment unit 5. The additivechamber 6 lies adjacent to the optional treatment unit 5.

Carbon dioxide, as CO₂ gas may be supplied from an industrial source asan additive in the additive chamber 6 and injected into the highlyreject saline water 18 in the treatment unit 5 to provide a desirablelevel of CO₂ in the water for subsequent use in algae growth and/orharvesting in the algae growth and harvesting chamber 8. The CO₂ may bederived through drilling processes during mining operations or othersources.

Municipal waste water may also be used as an additive in the additivechamber 6. Part of the treated waste having low salinity may be fed foruse in saline tolerant plant farming or algae growth in the algae growthand harvesting chamber 8.

In another embodiment the containers comprising the additive chamber 6may have a separate control valve 13 for each container in the additivechamber 6. The control valve 13 controls the flow rate of addition ofadditives in the additive chamber 6 to the treatment unit 5. The flowrate may be reduced or increased by the control valve 13 if more or lessadditives need to be introduced to the treatment unit 5. After passingthrough the treatment unit 5 the highly saline reject water 18 is sentto a bioreactor containing microalgae 7.

Once the water having adjusted salinity 18 is at a desired salinitylevel, CO₂ level, pH level, and nutrient level, it may be fed to aplurality of bioreactors 7. The bioreactors 7 may take the form ofincluding but not limited to ponds, preferably covered ponds. Thebioreactors 7 may include a combination of a bioreactor and a subsequentpond in combination. Each of the bioreactors 7 houses microalgae, whichmay be the same or different. Multiple streams of different watersalinity are provided for optimum production of algae in each case. Thebioreactor 7 may be a batch, a fed batch, or a continuous bioreactor.Preferably the bioreactor 7 is a fed batch bioreactor.

The stream of highly reject saline water 18 is treated in the treatmentunit 5 to provide the proper pH levels and have sufficient levels ofCO₂. This may enable some species preferred for ethanol production andsome species for biodiesel production to be harvested. The Botryococcusspecies is suitable for ethanol production but has a longer growth timewhich requires a separated flow from other species selected forbiodiesel feedstock. The biodiesel species, in particular Chloralla andSpirulina have a short growth time. Each of the bioreactors 7 comprisesan algae which may be of the same or different species. Multiple streamsof different water salinity from the treatment unit 5 are providedseparately or at the same time to each bioreactor 7 in order to providethe preferred growth rate of the algae. Algae species that are grown inthe bioreactor include but are not limited to Acaryochloris, Amphora,Anabaena, Anacystis, Anikstrodesmis, Botryococcus, Chaetoceros,Chlorella, Chlorococcum, Crocosphaera, Cyanotheca, Cyclotella,Cylindrotheca, Dunaliella, Euglena, Hematococcus, Isochrysis, Lyngbya,Microcystis, Monochrysis, Monoraphidium, Nannochloris, Nannochloropsis,Navicula, Nephrochloris, Nephroselmis, Nitzschia, Nodularia, Nostoc,Oochromonas, Oocystis, Oscillartoria, Pavlova, Phaeodactylum,Platymonas, Pleurochrysis, Porhyra, Prochlorococcus, Pseudoanabaena,Pyramimonas, Selenastrum, Stichococcus, Synechococcus, Synchocystis,Thalassiosira, Thermosynechocystis, and Trichodesmium species. Residencetime of the algae in the bioreactors 7 is in the range of 4-14 days,6-13 days, and 7-10 days. Preferably residence time of the algae in thebioreactors 7 is in the range of 7-10 days.

In another embodiment the highly reject saline water 18 passes directlyfrom the water purification system 2 to the bioreactor containingmicroalgae 7 and does not pass through a treatment unit.

The bioreactor containing microalgae 7 uses the highly reject salinewater 18 to produce a stream of biomass 19 that enters an algae growthand harvesting chamber 8.

In the algae growth and harvesting chamber 8, a concentrated biomass 20is grown and harvested. Preferably the biomass is algae. The biomass isgrown, cultivated and/or harvested by providing the factors thatinfluence the occurrence, growth, and production yield of algae orbiomass. Factors that influence the occurrence, growth, and productionyield of algae or biomass include carbon dioxide gas from a carbondioxide source 10 and light from a light source 9. The carbon dioxidesource 10 is preferably from industrial exhausts that produce highamounts of carbon dioxide to reduce the adverse environmental effects orthe green house effect of carbon dioxide. The light source 9 may be fromsolar energy or from a UV lamp. Temperature favoring algae or biomassgrowth is also regulated. The temperature is in the range of 10-80° C.,12-40° C., or 16-27° C. Preferably the temperature inside the algaegrowth and harvesting chamber 8 is in the range of 16-27° C.

The algae growth and harvesting chamber 8 produces the stream ofconcentrated biomass 20. The flow rate of the stream of concentratedbiomass may be controlled by a control valve 28. The control valve 28controls the flow rate of addition of the stream of concentrated biomass20 to a waste water processing unit 11. The flow rate may be reduced orincreased by the control valve 28 if more or less of the stream ofconcentrated biomass 20 needs to be added to the waste water processingunit 11.

The stream of concentrated biomass 20 is delivered to the waste waterprocessing unit 11. The stream of concentration biomass 20 has a higheralgae concentration than the stream of biomass that entered the algaegrowth and harvesting chamber 8. The waste water processing unitseparates a stream of purified water 21 from a stream of watercomprising heavy metals 24 using an algal mat that is formed from thestream of concentrated biomass 20. The algal mat comprises a pluralityof layers of algae. The algal mat may have at least 10 layers of algaeand may comprise a plurality of algal species.

In one embodiment the algal mat acts as a filter in the waste waterprocessing unit 11 to create a stream of purified water 21 and todiscard the metal ions from the waste water 23 to an extract remainingmetals unit 12. A control valve 31 controls the flow rate of addition ofthe stream of water comprising heavy metals 24 to the extract remainingmetals unit 12. The flow rate may be reduced or increased by the controlvalve 31 if more or less of the stream of water comprising heavy metals24 needs to be added to the extract remaining metals unit 12. A group ofmetals 25 that is produced from the extract remaining metals unit 12 isthe metal that is removed out of the algal biomass and from a gold orefrom the gold mining production system 4. The algal mat also comprisesoil which can be used to produce biodiesel and bioethanol afterextraction. Preferably the algal mat comprises 50% oil andcarbohydrates.

In another embodiment the algal mat acts as a filter in the gold miningproduction system 4 to separate a gold product 22 from waste and othermetals. In the gold mining production system 4 the gold from the goldore contacts the algal mat and attaches to the algal mat. Preferably allother materials in the gold ore pass through the algal mat, leaving thegold product 22 attached to the algal mat.

The remaining waste water which has heavy metals is delivered to thewaste water processing unit 11. The waste water processing unit 11removes suspended metals from the stream of concentrated biomass 20through algal biomass as a filter and purified water 21 that isdelivered to the gold mining production system 4. The flow rate of thestream of purified water 21 may be controlled by a control valve 26. Thecontrol valve 26 controls the flow rate of addition of the stream ofpurified water 21 to the gold mining production system 4. The flow ratemay be reduced or increased by the control valve 26 if more or less ofthe stream of purified water 21 needs to be added to the gold miningproduction system 4.

The gold mining production system separates gold from a gold ore by amethod including but not limited to gold cyanidation, CIL circuitprocess, thiosulfate leaching, or a bulk leach extractable gold process.The gold mining production system 4 uses the stream of purified water 21and the purified water from the purified water reservoir 3 to separateother metal ions in the gold ore from the gold.

In another embodiment the gold mining production system uses the methodof CIL circuit process to separate the gold product 22 from the goldore. Activated carbon is a highly porous material with distinctadsorptive properties. Gold complexes with either chloride or cyanideare strongly adsorbed by activated carbon. Gold recovery from solutionby granular, begins by loading, or adsorbing the gold onto the activatedcarbon, which is accomplished in the carbon-in-leach (CIL) circuit. TheCIL activated carbon system involves adding the carbon to the ore slurryin leaching tanks. The carbon adsorbs the gold from the solution ascyanidation of the ore proceeds.

In another embodiment the gold mining production system 4 uses the algalmat produced from the stream of concentrated biomass 20 to separate thegold product 22 from the gold ore. In one embodiment the algal mat ispresent in a sluice-type arrangement to separate the gold product 22from the gold ore. The sluice box comprises riffles that may be coatedwith algae or algal biomass to capture gold particles as they passthrough the sluice-type arrangement. In another embodiment the algal matcomprises a plurality of algal layers in the range of 1-10,000 layers ofalgae. Preferably the algal mat comprises 10-200 layers of algae. Inanother embodiment the algal mat may reduce the concentrations ofpotentially deleterious elements or metals including but not limited toaluminum, iron, manganese, nickel, zinc, and copper from the gold ore by5- and 10-fold. The algal mat may separate the metals or elements fromthe gold ore by passing the gold ore through the algal mat. The metalsthen adhere to individual filaments of the algal mat. The structure ofthe biomass formed may act as carpeting grown on the riffles in thesluice-type arrangement. The algal mat comprises carbohydrates andproteins from the algae including but not limited to sulfate groups,carboxylate, and sulfhydryl. The positively charged heavy metalsincluding gold from the gold ore bond to the negatively charged ions inthe algal mat and the remaining materials from the gold ore pass throughthe algal mat without bonding to the algal mat. The remaining materialsfrom the gold ore pass to the extract remaining metals unit 12.

In another embodiment an individual layer of the algal mat has a lengthin the range of 50-500 cm, 75-250 cm, or 90-150 cm. The algal mat has awidth in the range of 50-500 cm, 75-250 cm, or 90-150 cm. Preferably theindividual layer of the algal mat has a length in the range of 95-125 cmand a width in the range of 95-125 cm. An individual layer of the algalmat has a depth in the range of 0.5-50 cm, 1.0-45 cm, or 5-40 cm.Preferably the individual layer of the algal mat has a depth in therange of 1.0-10 cm.

The gold mining production system 4 separates a stream of waste water 23comprising the metal ions from a gold product 22. The gold product 22then exits the gold mining production system 4. The stream of wastewater 23 is delivered to the waste water processing unit 11. The flowrate of the stream of waste water 23 may be controlled by a controlvalve 29. The control valve 29 controls the flow rate of addition of thestream of waste water 23 to the waste water processing unit 11. The flowrate may be reduced or increased by the control valve 29 if more or lessof the stream of waste water 23 needs to be added to the waste waterprocessing unit 11. In one embodiment metal ions are separated from thegold in the gold ore in the gold mining production system 4. The metalions are separated from the gold in the gold ore by an algal mat. Thealgal mat traps the metal ions and isolates the metal ions. The goldpasses through the algal mat to produce a gold product 22. After thealgal mat isolates the metal ions, the metal ions are sent to theextract remaining metals unit 12. A stream of metals 25 is produced fromthe extract remaining metals unit 25.

Algae are modest microbes with amazing potential. They thrive in turbid,brackish water environments with little more than basic nutrients andsunshine. They grow far more rapidly than conventional crops, andgenerate a much higher fraction of their biomass as oil (up to 60%,versus 2%-3% for soybeans).

In one embodiment the disclosure describes a process for using salinewater, and saline reject water produced in water purification, to usefor gold mining production, and growing and harvesting algae. Also, thesystem describes an improved method for growing and harvesting algaewith the use of saline water as growth medium for recycling waste waterin order to extract the remaining metals out of waste water.Furthermore, the harvested algae may be used in various types anddifferent categories of applications including but not limited to waterpurification systems for gold mining production, and extract metals outof remaining waste water.

Thus, the foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. As will be understood by thoseskilled in the art, the present invention may be embodied in otherspecific forms without departing from the spirit or essentialcharacteristics thereof. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting of the scopeof the invention, as well as other claims. The disclosure, including anyreadily discernible variants of the teachings herein, define, in part,the scope of the foregoing claim terminology such that no inventivesubject matter is dedicated to the public.

The invention claimed is:
 1. A method for gold mining and algaeproduction, the method comprising: (a) treating a first salt waterstream having a first salt concentration X, wherein the treating iscarried out with at least one of electrodialysis reversal, reverseosmosis, and mechanical vapor compression in a first water purificationsystem to form: (i) a first purified water stream having a second saltconcentration Y lower than X, and (ii) a first saline water streamhaving a third salt concentration Z higher than X, (b) treating a goldore with the first purified water stream to separate gold from the goldore and form a waste water comprising metal ions in a gold miningproduction system, (c) treating the first saline water stream in asecond water purification system connected to the first waterpurification system to form a second saline water stream and a secondpurified water stream, wherein the second purified water stream has afourth salt concentration A lower than Z, and the second saline waterstream has a fifth salt concentration B higher than Z, (d) feeding thesecond saline water stream to a bioreactor containing algae to form afirst algae biomass in the saline water of the second saline waterstream, (e) feeding the first algae biomass to an algae growth andharvesting chamber to grow the first algae biomass and form aconcentrated algae biomass, (f) feeding the concentrated algae biomassto a waste water processing unit, wherein the concentrated algae biomassforms a first algae mat in the waste water processing unit, (g) feedingthe waste water comprising the metal ions from the gold miningproduction system to the waste water processing unit, wherein the firstalgae mat in the waste water processing unit filters the waste water toform (i) a third purified water stream and (ii) the first algae matbound to the metal ions, (h) feeding the third purified water stream tothe gold mining production system for treating the gold ore, (i)removing the first algae mat bound to the metal ions from the wastewater processing unit, (j) extracting the metal ions bound to the firstalgae mat to produce at least one metal, and (k) feeding theconcentrated algae biomass from the algae growth and harvesting chamberto the gold mining production system to form a second algae mat in thegold mining production system, wherein the gold mining production systemfurther comprises at least one sluice box comprising a plurality ofriffles, and wherein the second algae mat contacts the gold ore andcoats the plurality of riffles to capture the gold separated from thegold ore contacting the second algae mat.
 2. The method of claim 1,further comprising: feeding the first purified water stream to apurified water reservoir to store purified water from the first purifiedwater stream, wherein the purified water reservoir is connected to thefirst water purification system and the gold mining production system;and supplying the gold mining production system with the purified waterfrom the purified water reservoir.
 3. The method of claim 1, furthercomprising: treating the second saline water stream with an additive ina treatment unit before feeding the second saline water stream to thebioreactor containing the algae, wherein the additive is at least oneselected from the group consisting of CO₂ gas, acids, and bases.
 4. Themethod of claim 1, further comprising: supplying to the algae growth andharvesting chamber at least one selected from the group consisting ofcarbon dioxide, UV light, and solar light.
 5. The method of claim 1,wherein the first algae mat and/or the second algae mat are formed fromthe concentrated algae biomass of the Botryococcus species, theChloralla species, and the Spirulina species.
 6. A method for goldmining and algae production, the method comprising: (a) treating a firstsalt water stream having a first salt concentration X, wherein thetreating is carried out with at least one of electrodialysis reversal,reverse osmosis, and mechanical vapor compression in a first waterpurification system to form: (i) a first purified water stream having asecond salt concentration Y lower than X, and (ii) a first saline waterstream having a third salt concentration Z higher than X, (b) treating agold ore with the first purified water stream to separate gold from thegold ore and form a waste water comprising metal ions in a gold miningproduction system, (c) treating the first saline water stream in asecond water purification system connected to the first waterpurification system to form a second saline water stream and a secondpurified water stream, wherein the second purified water stream has afourth salt concentration A lower than Z, and the second saline waterstream has a fifth salt concentration B higher than Z, (d) feeding thesecond saline water stream to a bioreactor containing algae to form afirst algae biomass in the saline water of the second saline waterstream, (e) feeding the first algae biomass to an algae growth andharvesting chamber to grow the first algae biomass and form aconcentrated algae biomass, (f) feeding the concentrated algae biomassto a waste water processing unit, wherein the concentrated algae biomassforms a first algae mat in the waste water processing unit, (g) feedingthe waste water comprising the metal ions from the gold miningproduction system to the waste water processing unit, wherein the firstalgae mat in the waste water processing unit filters the waste water toform (i) a third purified water stream and (ii) the first algae matbound to the metal ions, (h) feeding the third purified water stream tothe gold mining production system for treating the gold ore, (i)removing the first algae mat bound to the metal ions from the wastewater processing unit, (j) extracting the metal ions bound to the firstalgae mat to produce at least one metal, (k) subjecting the gold ore toa gold cyanidation process to separate gold from the gold ore in thegold mining production system, wherein the gold in the gold ore isconverted to a gold-cyanide complex soluble in purified water from thefirst purified water stream and the third purified water stream, and (l)feeding the concentrated algae biomass from the algae growth andharvesting chamber to the gold mining production system to form a secondalgae mat in the gold mining production system, wherein the second algaemat contacts the gold-cyanide complex and binds positively charged goldion in the gold-cyanide complex.
 7. The method of claim 6, furthercomprising: feeding the first purified water stream to a purified waterreservoir to store purified water from the first purified water stream,wherein the purified water reservoir is connected to the first waterpurification system and the gold mining production system; and supplyingthe gold mining production system with the purified water from thepurified water reservoir.
 8. The method of claim 6, further comprising:treating the second saline water stream with an additive in a treatmentunit before feeding the second saline water stream to the bioreactorcontaining the algae, wherein the additive is at least one selected fromthe group consisting of CO₂ gas, acids, and bases.
 9. The method ofclaim 6, further comprising: supplying to the algae growth andharvesting chamber at least one selected from the group consisting ofcarbon dioxide, UV light, and solar light.
 10. The method of claim 6,wherein the first algae mat and/or the second algae mat are formed fromthe concentrated algae biomass of the Botryococcus species, theChloralla species, and the Spirulina species.
 11. A gold mining andalgae production system, comprising: (a) a first water purificationsystem for treating a first salt water stream having a first saltconcentration X to form a first purified water stream having a secondsalt concentration Y lower than X and a first saline water stream havinga third salt concentration Z higher than x, (b) a bioreactor containingalgae and in fluid communication with the first water purificationsystem, wherein the bioreactor is capable of receiving the first salinewater stream from the first water purification system and growing thealgae in the saline water of the first saline water stream to form afirst algae biomass, (c) an algae growth and harvesting chamber in fluidcommunication with the bioreactor, wherein the algae growth andharvesting chamber is capable of receiving the first algae biomass fromthe bioreactor and growing the first algae biomass to form aconcentrated algae biomass, (d) a gold mining production system in fluidcommunication with the first water purification system and in fluidcommunication with the algae growth and harvesting chamber, wherein thegold mining production system is capable of receiving the first purifiedwater stream from the first water purification system and treating agold ore with the first purified water stream to separate gold from thegold ore and form a waste water comprising metal ions, wherein the goldmining production system is capable of receiving the concentrated algaebiomass from the algae growth and harvesting chamber and furthercomprises a second algae mat formed from the concentrated algae biomassand being capable of contacting the gold ore, and wherein the goldmining production system further comprises at least one sluice boxcomprising a plurality of riffles coated by the second algae mat forcapturing the gold separated from the gold ore, (e) a waste waterprocessing unit in fluid communication with the algae growth andharvesting chamber and in fluid communication with the gold miningproduction system, wherein the waste water processing unit is capable ofreceiving the concentrated algae biomass from the algae growth andharvesting chamber and the waste water comprising the metal ions fromthe gold mining production system, and (f) a first algae mat formed fromthe concentrated algae biomass in the waste water processing unit,wherein the first algae mat is capable of filtering the waste watercomprising the metal ions to form a third purified water stream and thefirst algae mat bound to the metal ions, and wherein the waste waterprocessing unit is capable of supplying the third purified water streamto the gold mining production system to treat the gold ore.
 12. Thesystem of claim 11, further comprising: a purified water reservoirconnected to the first water purification system and the gold miningproduction system, wherein the purified water reservoir is capable ofstoring purified water of the first purified water stream from the firstwater purification system and supplying the purified water to the goldmining production system.
 13. The system of claim 12, furthercomprising: a second water purification system connected to the firstwater purification system and the purified water reservoir, wherein thesecond water purification system is capable of receiving and treatingthe first saline water stream having the third salt concentration Z fromthe first water purification system to form a second purified waterstream having a fourth salt concentration A lower than Z and a secondsaline water stream having a fifth salt concentration B higher than Zand is capable of supplying the second purified water stream to thepurified water reservoir.
 14. The system of claim 13, furthercomprising: (a) a treatment unit in fluid communication with the secondwater purification system and the bioreactor, and (b) an additivechamber connected to the treatment unit via a valve, wherein theadditive chamber is capable of storing additives and dispensing theadditives to the treatment unit at a flow rate controlled by the valve,and wherein the treatment unit is capable of receiving the second salinewater stream from the second water purification system and treating thesecond saline water stream with the additives dispensed from theadditive chamber via the valve to form an additive-treated second salinewater stream, wherein the treatment unit is capable of feeding theadditive-treated second saline water stream to the bioreactor.
 15. Thesystem of claim 11, further comprising: a carbon dioxide source forsupplying carbon dioxide gas to the algae growth and harvesting chamber,and a light source for supplying light in the form of UV and/or solarlight to the algae growth and harvesting chamber.
 16. The system ofclaim 11, further comprising: an extract remaining metals unit forextracting the metal ions bound to the first algal mat to produce atleast one metal.
 17. The system of claim 11, wherein the first algae matand/or the second algae mat are formed from the concentrated algaebiomass of the Botryococcus species, the Chloralla species, and theSpirulina species.